As females get smaller, they become less fecund. They also are not able to bury eggs as deep. Given the same freshet, the smaller females will suffer more scour. Fewer fry produced.

Productivity is not a fixed point but rather moving as situations change. I keep using the AL/pink relationship. At a constant 60% harvest rate the coho produced 1,000-8,000 harvest depending on pink escapement for the fry.

To me, that says that our current situation, with somewhat degraded habitat, regulated flows, lack of MDN gives one level of productivity. Change any ONE of those and you move productivity to a different level.

If we want those 18,000 springers in the Skagit then we need to recreate the conditions under which they lived and this would include the whole ocean as well as land. If we don't want to do that, then we get something different.